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   <div id="projectname">Oboe
   &#160;<span id="projectnumber">1.2</span>
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   <div id="projectbrief">A library for creating real-time audio apps on Android</div>
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<li class="navelem"><a class="el" href="namespaceoboe.html">oboe</a></li><li class="navelem"><a class="el" href="classoboe_1_1_latency_tuner.html">LatencyTuner</a></li>  </ul>
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<a href="#pub-methods">Public Member Functions</a> &#124;
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<div class="title">oboe::LatencyTuner Class Reference</div>  </div>
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<p><code>#include &lt;<a class="el" href="_latency_tuner_8h_source.html">LatencyTuner.h</a>&gt;</code></p>
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Public Member Functions</h2></td></tr>
<tr class="memitem:a0263b9a55825c0a403653b2b508073ea"><td class="memItemLeft" align="right" valign="top">&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_latency_tuner.html#a0263b9a55825c0a403653b2b508073ea">LatencyTuner</a> (<a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> &amp;stream)</td></tr>
<tr class="separator:a0263b9a55825c0a403653b2b508073ea"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ab437bd10605af9e5733d043f8adc0b43"><td class="memItemLeft" align="right" valign="top">&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_latency_tuner.html#ab437bd10605af9e5733d043f8adc0b43">LatencyTuner</a> (<a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> &amp;stream, int32_t maximumBufferSize)</td></tr>
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<tr class="memitem:ad2be756965e6a9af3114008eda892174"><td class="memItemLeft" align="right" valign="top"><a class="el" href="namespaceoboe.html#a486512e787b609c80ba4436f23929af1">Result</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_latency_tuner.html#ad2be756965e6a9af3114008eda892174">tune</a> ()</td></tr>
<tr class="separator:ad2be756965e6a9af3114008eda892174"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a6c0142e08dc65eda8f758b4794450867"><td class="memItemLeft" align="right" valign="top">void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_latency_tuner.html#a6c0142e08dc65eda8f758b4794450867">requestReset</a> ()</td></tr>
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<tr class="memitem:a45c013fd6787ad09d328385d6314c4d4"><td class="memItemLeft" align="right" valign="top">bool&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_latency_tuner.html#a45c013fd6787ad09d328385d6314c4d4">isAtMaximumBufferSize</a> ()</td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p><a class="el" href="classoboe_1_1_latency_tuner.html">LatencyTuner</a> can be used to dynamically tune the latency of an output stream. It adjusts the stream's bufferSize by monitoring the number of underruns.</p>
<p>This only affects the latency associated with the first level of buffering that is closest to the application. It does not affect low latency in the HAL, or touch latency in the UI.</p>
<p>Call <a class="el" href="classoboe_1_1_latency_tuner.html#ad2be756965e6a9af3114008eda892174">tune()</a> right before returning from your data callback function if using callbacks. Call <a class="el" href="classoboe_1_1_latency_tuner.html#ad2be756965e6a9af3114008eda892174">tune()</a> right before calling write() if using blocking writes.</p>
<p>If you want to see the ongoing results of this tuning process then call stream-&gt;getBufferSize() periodically. </p>
</div><h2 class="groupheader">Constructor &amp; Destructor Documentation</h2>
<a id="a0263b9a55825c0a403653b2b508073ea"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a0263b9a55825c0a403653b2b508073ea">&#9670;&nbsp;</a></span>LatencyTuner() <span class="overload">[1/2]</span></h2>

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          <td class="memname">oboe::LatencyTuner::LatencyTuner </td>
          <td>(</td>
          <td class="paramtype"><a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> &amp;&#160;</td>
          <td class="paramname"><em>stream</em></td><td>)</td>
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<p>Construct a new <a class="el" href="classoboe_1_1_latency_tuner.html">LatencyTuner</a> object which will act on the given audio stream</p>
<dl class="params"><dt>Parameters</dt><dd>
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    <tr><td class="paramname">stream</td><td>the stream who's latency will be tuned </td></tr>
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  </dd>
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<h2 class="memtitle"><span class="permalink"><a href="#ab437bd10605af9e5733d043f8adc0b43">&#9670;&nbsp;</a></span>LatencyTuner() <span class="overload">[2/2]</span></h2>

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          <td class="memname">oboe::LatencyTuner::LatencyTuner </td>
          <td>(</td>
          <td class="paramtype"><a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> &amp;&#160;</td>
          <td class="paramname"><em>stream</em>, </td>
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          <td class="paramkey"></td>
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          <td class="paramtype">int32_t&#160;</td>
          <td class="paramname"><em>maximumBufferSize</em>&#160;</td>
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          <td>)</td>
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<p>Construct a new <a class="el" href="classoboe_1_1_latency_tuner.html">LatencyTuner</a> object which will act on the given audio stream.</p>
<dl class="params"><dt>Parameters</dt><dd>
  <table class="params">
    <tr><td class="paramname">stream</td><td>the stream who's latency will be tuned </td></tr>
    <tr><td class="paramname">the</td><td>maximum buffer size which the <a class="el" href="classoboe_1_1_latency_tuner.html#ad2be756965e6a9af3114008eda892174">tune()</a> operation will set the buffer size to </td></tr>
  </table>
  </dd>
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<h2 class="groupheader">Member Function Documentation</h2>
<a id="a45c013fd6787ad09d328385d6314c4d4"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a45c013fd6787ad09d328385d6314c4d4">&#9670;&nbsp;</a></span>isAtMaximumBufferSize()</h2>

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          <td class="memname">bool oboe::LatencyTuner::isAtMaximumBufferSize </td>
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<dl class="section return"><dt>Returns</dt><dd>true if the audio stream's buffer size is at the maximum value. If no maximum value was specified when constructing the <a class="el" href="classoboe_1_1_latency_tuner.html">LatencyTuner</a> then the value of stream-&gt;getBufferCapacityInFrames is used </dd></dl>

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<h2 class="memtitle"><span class="permalink"><a href="#a6c0142e08dc65eda8f758b4794450867">&#9670;&nbsp;</a></span>requestReset()</h2>

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          <td class="memname">void oboe::LatencyTuner::requestReset </td>
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<p>This may be called from another thread. Then <a class="el" href="classoboe_1_1_latency_tuner.html#ad2be756965e6a9af3114008eda892174">tune()</a> will call reset(), which will lower the latency to the minimum and then allow it to rise back up if there are glitches.</p>
<p>This is typically called in response to a user decision to minimize latency. In other words, call this from a button handler. </p>

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<h2 class="memtitle"><span class="permalink"><a href="#ad2be756965e6a9af3114008eda892174">&#9670;&nbsp;</a></span>tune()</h2>

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          <td class="memname"><a class="el" href="namespaceoboe.html#a486512e787b609c80ba4436f23929af1">Result</a> oboe::LatencyTuner::tune </td>
          <td>(</td>
          <td class="paramname"></td><td>)</td>
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<p>Adjust the bufferSizeInFrames to optimize latency. It will start with a low latency and then raise it if an underrun occurs.</p>
<p>Latency tuning is only supported for AAudio.</p>
<dl class="section return"><dt>Returns</dt><dd>OK or negative error, ErrorUnimplemented for OpenSL ES </dd></dl>

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<hr/>The documentation for this class was generated from the following file:<ul>
<li>include/oboe/<a class="el" href="_latency_tuner_8h_source.html">LatencyTuner.h</a></li>
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